Technical information

UGH021/0301 VL Series Portable Chillers, 2 to 40 Tons
Page: 39
5.6 CHECKING THE REFRIGERANT CHARGE
A. All standard Conair chillers are manufactured with thermostatic
expansion valves as the metering device to the evaporator.
B. All Conair chillers have a refrigerant sight glass with a moisture
indicator. To check the refrigerant charge under normal operating
conditions:
1. Remove the plastic cap covering the sight glass, if installed.
2. Start the chiller and allow system pressures and
temperatures to stabilize.
3. With the unit operating at 100% capacity (not in the “hot
gas bypass” mode) the sight glass should appear clear with
no foam or bubbles evident. If foam or bubbles are evident,
the chiller has suffered from a loss of refrigerant and should
be checked by a qualified refrigeration technician.
4. The “dot” in the middle of the sight glass is the moisture
indicator. It should appear green at all times. A white or
yellow color indicates moisture has invaded the
refrigeration system, which is detrimental to the life of the
compressor. The filter-drier should be replaced by a
qualified refrigeration technician.
Figure 5.6A
Typical refrigerant sight glass (cap removed)
Moisture
Indicator